Why does botox not work for some people?

Several factors can contribute: the dose may not have been sufficient for your sphincter, the injection site may not have targeted the area of spasm effectively, the sphincter pressure may be too high for botox alone to overcome, or the fissure may have developed features (deep scarring, poor blood supply) that prevent healing even with adequate sphincter relaxation. In some cases, the cause is unclear.

Should I try a second botox injection?

This depends on how you responded to the first. If there was partial improvement — some reduction in pain and spasm but not enough for complete healing — a second injection may provide the additional benefit needed. If there was no improvement at all, most surgeons will discuss surgery rather than repeating the same approach.

What surgical options are there after botox fails?

The main surgical options are lateral internal sphincterotomy (LIS), which has the highest healing rate, and fissurectomy (sometimes combined with botox). LIS permanently reduces sphincter pressure. Fissurectomy removes the chronic fissure tissue. Your surgeon will discuss which is most appropriate for your specific situation.

Does botox failing mean surgery will not work either?

No. Botox and surgery work differently. Botox provides temporary, partial sphincter relaxation. LIS surgery provides permanent, more complete reduction in sphincter pressure. Many people whose fissures did not respond to botox go on to heal successfully after surgery. The healing rates for LIS are generally above 90 percent.

Botox didn't work: what now

At a glance

When botox does not heal a fissure, it is disappointing but not unusual — botox works for roughly 50 to 70 percent of people. This guide covers what the options are from here, why botox may not have worked, and how to approach the next conversation with your surgeon.

Understanding why

Botox may not heal a fissure for several reasons:

Insufficient sphincter relaxation — the dose or injection site may not have adequately relaxed the muscle
Very high sphincter pressure — some people have resting pressure that is too high for botox alone to address
Chronic fissure features — deep scarring, fibrosis, or poor blood supply in the fissure bed that prevents healing even with adequate relaxation
The fissure healed but recurred — the botox wore off before the healing was complete or permanent

Importantly, botox not working does not mean the fissure is untreatable. It means a different approach is needed.

The options

Second botox injection

Appropriate when:

The first injection provided partial improvement
The fissure healed but recurred after the botox wore off
The surgeon believes a different dose or technique may help

Not appropriate when:

The first injection provided no benefit at all
Two injections have already been tried

Lateral internal sphincterotomy (LIS)

The most effective surgical treatment for chronic fissures:

How it works: A small, controlled cut in the internal sphincter permanently reduces resting pressure
Success rate: Generally described as above 90 percent for chronic fissures
Recovery: One to two weeks off work for most people; full healing over four to eight weeks
Risk: A small risk of changes in gas or stool control. Your surgeon will discuss this in detail.

LIS is typically the next recommendation when botox has failed.

Fissurectomy

Removal of the chronic fissure tissue, sometimes combined with botox or a sphincterotomy:

How it works: The scar tissue and chronic fissure bed are excised, creating a fresh wound that can heal normally
When it is chosen: When the fissure has significant scar tissue, a large sentinel pile, or when combined with other approaches
Recovery: Similar to LIS, though the open wound takes longer to heal

Continued conservative care

In some cases — particularly if the fissure is not severely symptomatic — people choose to continue managing with dietary measures and topical treatments rather than proceeding to surgery. This is a valid choice, particularly if quality of life is acceptable with management.

The conversation with your surgeon

Questions worth asking:

Why do you think botox did not work in my case?
Do you recommend a second injection or surgery?
If surgery, which procedure and why?
What is the specific success rate for my situation?
What are the risks, particularly regarding continence?
What is the recovery timeline?

Moving forward

The progression from conservative treatment to botox to surgery is a standard treatment pathway. Each step provides information about what the fissure needs. Reaching the point of considering surgery does not represent a failure — it represents a thorough approach that has narrowed down the right treatment.